Can You Really Drink Too Much Water?

College man drinking water to stay hydrated.
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Question: I know it's important to drink water, and I do my best to increase my water intake every day. My concern is whether or not I can drink too much. How do I know if I'm drinking too much water? Will I get sick?

Answer:  You need to drink plenty of water each for your body's various biological processed to function properly. But, you weren't designed to get all (or almost all) of the water you need for an entire day all at one sitting.

 

Drinking too much water can cause a life-threatening condition called hyponatremia, which is sometimes called water intoxication. Hyponatremia literally means "low sodium in the blood." It occurs when someone drinks enormous amounts of water and loses too much salt from the body in a short time.

It isn't so much about the total quantity for the day, but the amount you drink per hour. A large intake of water in a short period overwhelms your kidneys so they can't process and eliminate the water fast enough, which drives your blood levels of sodium too low.

Severe sodium deficiency can lead to twitching, seizures, and even death. A person with hyponatremia needs to see a doctor for immediate diagnosis and treatment.

Hyponatremia won't happen to a healthy person who sips on several glasses of water throughout the day. It can occur when marathon runners drink gallons of water and don't replace the electrolytes during a race, or when people with certain psychological disorders can't stop themselves from drinking water.

 It can also occur in the elderly and can happen with certain medical conditions.

How to Prevent Hyponatremia

Preventing water intoxication is easy. Drink the water your body needs, but don't drink any more than that. There's no reason to gulp down several glasses of water all at once. Take your time.

You can usually tell if you need more water by whether or not you are thirsty. The color of your urine can also tip you off -- If your urine is pale yellow, you're just fine. If your urine is dark yellow or gold in color, then you need to drink more water.

Sometimes looking at the color of your urine won't work. For example, if you take a dietary supplement that contains a B-complex vitamin called riboflavin, you'll probably notice your urine turns bright yellow in color shortly after you take the supplement. Certain medications can change the color of urine as well. 

Watch your water intake when you're exercising intensely or working in extreme heat. Don't drink more than 30 ounces (about four cups) per hour under these conditions.  

Another way to reduce your risk of hyponatremia is to drink sports drinks with electrolytes instead of plain water. They'll help keep your potassium and sodium levels about where they need to be while you replace the lost fluids. Or eat a little food with your water.

And finally, speak with your doctor if you have a medical condition that involved your kidneys or your adrenal glands, or if you take an antidiuretic. He or she will explain how much water you should be drinking every day.

Source:

American Family Physician. "Management of Hyponatremia."  http://www.aafp.org/afp/2004/0515/p2387.html.

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